There is conventionally known a connector for connecting a plastic hose to a pipe provided on a housing of a radiator of an automobile comprising a cylindrical sleeve to which the hose is connected; and a securing device attached movably between a connected position and a disconnected position on the cylindrical sleeve, and provided with an arm for locking the hose in the connected position (see Patent Document 1).
In this connector, the arm of the securing device is formed so as to bend elastically in a radial direction, and in the case when the securing device is in the connected position, a rib protruding on the outer perimeter surface of the hose is insertion-coupled to a recess on the inside of the radial direction of a hook provided on one end side of the arm, an inclined surface on the outside of the radial direction of the hook contacts with an inner edge (edge on the inside of the radial direction) of a hole on the cylindrical sleeve, and bending to the outside of the radial direction of the arm (that is, releasing of the insertion-coupling of the rib) is prevented. On the other hand, when a user moves the securing device from the connected position to the disconnected position, the contact of the hook of the arm with the hole of the cylindrical sleeve is released by relative movement between the securing device and the cylindrical sleeve, the hook rides past the rib so that the arm is pushed wider to the outside of the radial direction by relative movement between the securing device and the hose, and the insertion-coupling of the rib to the recess of the hook is released.